Arbitrary bending PU potting adhesive for LED strip

INTRODUCTION

PU-248 is a two-component, colorless clear, flexible, very soft, low viscosity, fast cure liquid polyurethane resin; it has excellent UV and yellow resistance property, weather resistant and anti-aging, form a bright crystal clear and smooth surface after cured. It is widely used in doming, casting, encapsulation, potting, and non-yellowing coating and so on , especially the soft LED strip.

UNCURED PROPERTIES

Item	PU-248A	PU-248B
Appearance	Colorless clear liquid	Colorless to yellowish liquid
Viscosity cps/25°C	3000 ±100	150 ± 50
Shelf life (month)	6	6
Mixing Ration (by weight)	A:B=1:1
Pot Life (at 25°C)	30min (for 200g mixture)
Cure condition	60°C×2.5h

CURED PROPERTIES

Item	PU-248
Appearance	Transparent and flexible
Hardness (Shore A)	30±5
Tensile strength (Mpa)	2
Elongation (%)	200
Volume resistivity (ohm-cm)	>1015

OPERATION DETAILS

It is very important to maintain the humidity of the operating environment. We recommend please do the operation as follow.

Pre-Processingthe base material which need to doming/potting/coating: put it into the 60°C oven to remove the moisture on the surface.Keep the container clean and dry which used to mixing the adhesive.Take the correct mix ratio amount of part A and part B, A:B=1:1 (by weight).Stir the mixture uniformly, and then do the operation of take off the gas immediately (use the vacuum pump to de-foaming), until there is no bubble on the surface of liquid.Please use up the mixture within the operation time, the more quantity of mixing, the less operation time.The operation of potting/doming: don’t potting in a high height, don’t potting in many different areas, just take a standpoint and potting the glue slowly. Doming: use clean needle to doming. If use the tube package product, just connect the mixing tube and doming, the usual thickness is about 2mm, observe the surface within 5min after doming, use the needle to remove the small bubbles if there have. Curing condition and time: 60°C×2.5h.During curing, please keep the environments cleaning to avoid the dirt dropping into the uncured glue.It is very important to seal the part A and part B well after use. And please take the basic protective measures when operation.